This invention relates to hands-free telephone systems, and more particularly, to a wireless hands-free conference telephone system adapted for signal connection to a conventional telephone unit.
Heretofore, hands-free type telephone systems have utilized wired transmission means to send a signal from a microphone or transducer into the conventional telephone transmission system. Wireless transmitting units have previously been used in mobile telephone systems for boats, automobiles and airplanes, and more recently, in portable personal phones. None of the mobile or personal telephone systems have been adopted for multi-person conference type sound pick up, but have been limited to close range, single person use.
Conventional conference type telephone systems having a hands-free sound pick-up unit with a microphone adapted for receiving voice or other transmission generated a substantial distance from the microphone have all been "wired" from the microphone to the conventional telephone circuitry. Patents directed to wired conference telephone systems and mobile radio telephone systems include U.S. Pat. Nos. 3,889,059; 4,225,754; 4,291,197; 4,319,086; and 4,363,935.
Existing wired conference telephone systems include a transducer-microphone which is adapted to pick up voice and other signals generated at a distance of about 5-15 feet from the microphone. But such units, by being wired to the "hands-free unit", are designed to be positioned on a credenza or other piece of furniture, preferably at the side of a room where the wire can be "out of sight". Other placement of a conference phone on desks, tables or the like, must contend with exposure of the wiring between the microphone and the hands-free control unit telephone. Such devices do not lend themselves to placement in the middle of a large conference table or other piece of furniture positioned "out in the open" in a room. If what may be considered an unsightly wiring placement is to be avoided, positioning a wired conference telephone microphone in the center of a conference table has heretofore necessitated the placement of a hole through the table top.
Heretofore, it was also believed that the use of microphones and speakers positioned in separate chasses facing each other would present feedback problems.
A need has arisen for a wireless microphone-transmitter which can be positioned in the middle of a conference table or on other types of furniture without the interference of exposed connecting wires, particularly for use in large conference rooms such as corporate board meeting rooms, and the like.
It is therefore an object of the present invention, generally stated, to provide an improved hands-free conference telephone system wherein the voice pick-up apparatus is remotely wirelessly positioned from the remainder of the conference telephone system.